Part 32

The above figures show several conditions. The first is that the arch is quite distinctly larger in the narrow than in the broad skulls in both sexes. The second fact is that the skull (vault) itself is slightly larger in the narrow-headed. The third is that the length of the arch is somewhat greater in the narrow and long skulls than it is in the broad and shorter, relatively to the skull size. The fourth is that there appears a close correlation, more particularly in the females, between the length of the arch and that of the skull.

FOOTNOTES:

[155] See Bull. 62, Bur. Am. Ethn., and writer's Report on an Additional Collection of Skeletal Remains from Arkansas and Louisiana, published with Clarence B. Moore's report on the Antiquities of the Ouachita Valley, Philadelphia, 1909.

THE BASION-NASION DIAMETER

The anterior basal length (basion-nasion) is a measurement of importance, though its full meaning in anthropology is not yet entirely clear. From data quoted by Martin (Lehrb., 715-716) it appears to average in whites up to 10.3 centimeters in males and up to 10.1 centimeters in females, and is known to correlate closely with the length of the vault. Secondarily it also correlates with stature.

Data on American Indians are not yet generally available, though in preparation. The Munsee skulls gave the writer for the diameter the means of 10.27 for the males and 10.02 for the females; the mound skulls from Arkansas and Louisiana gave 10.45 for the males and 9.77 for the females.

An abstract of the data on the Eskimo skulls is given in the next table. The values for the measurement are rather high, especially for such short people. The percentage relation of the measurement to the length of the skull appears also to be high. Manouvrier (1882, quoted in Martin, Lehrb., 716) found this relation in French skulls to be _53.6_ in the males and _54.7_ in the females.

ESKIMO CRANIA: BASION-NASION LENGTH

+-------------------+------------------- | Groups of males | Corresponding | | groups of females +--------+----------+--------+---------- | | Its | | Its | Basion-|percentage| Basion-|percentage | nasion | relation | nasion | relation |diameter|to length |diameter|to length | | of skull | | of skull ---------------------------------+--------+----------+--------+---------- | (13) | (13) | (13) | (13) Southwestern and Midwestern | 10.38 | _56.4_ | 9.85 | _55.7_ | (6) | (6) | (6) | (6) Northwestern | 10.58 | _56.4_ | 10.06 | _56.3_ | (5) | (5) | (5) | (5) Northern Arctic and northeastern | 10.65 | _56.2_ | 10.06 | _55.4_ ---------------------------------+--------+----------+--------+----------

The female measurement to that of the male, in the Eskimo, is as _94.9_ to 100. As a similar relation of the cranial modules in the two sexes is close to _95.7_, the anterior basal length would seem to be at a little disadvantage in the female Eskimo skull.

The same condition is seen also when the basion-nasion diameter is compared with the length of the skull. In the males, notwithstanding the fact that the length of the vault is increased through the development of the frontal sinuses and not infrequently also through that of the occipital ridges, the percentage relation of the basion-nasion to the maximum total length of the vault is approximately _56.3_, in the females but _55.8_. It seems therefore safe to say that in the Eskimo, in general, that part of the brain anterior to the foramen magnum is relatively somewhat better developed in the males than in the females.

But to this there are some exceptions. Thus it may be seen in the general table which follows that in the northwestern groups conditions in this respect are equalized; and in the succeeding detailed table it will be noted that while the males exceed the females in this particular in 14 of the groups, in 5 groups conditions are equal (or within one decimal), and in 5 the female percentage exceeds slightly that in the males. In the numerically best represented groups conditions are nearly equal, with the males nevertheless slightly favored.

ESKIMO SKULLS: BASION-NASION LENGTH AND ITS RELATION TO LENGTH OF SKULL

SEXES SEPARATELY IN ASCENDING ORDER

+--------------+-------------- | Males | Females +--------------+-------------- | B-N. | B-N. |BN×100/Skull l|BN×100/Skull l -----------------------------+--------------+-------------- _Southwestern | | and Midwestern_ | | | (4) | (7) Little Diomede Island | 10.18 _56.2_| 9.91 _54.9_ | (3) | (2) Chukchee | 10.20 _54.8_| 10.00 _54.8_ | (3) | (3) Pilot Station (Yukon) | 10.27 _54.3_| 9.97 _56_ | (9) | (4) Hooper Bay | 10.29 _57.6_| 9.70 _55.7_ | (4) | (6) Mumtrak | 10.32 _57_ | 9.52 _55.1_ | (146) | (133) St. Lawrence Island | 10.36 _56.3_| 9.93 _56.1_ | (3) | Yukon Delta | 10.37 _55.8_| | (11) | (18) Pastolik | 10.41 _56.5_| 9.98 _56.3_ | (8) | (6) St. Michael Island | 10.44 _57.3_| 9.98 _56.3_ | (9) | (15) Nelson Island | 10.46 _55.8_| 9.73 _55.9_ | (3) | (7) Togiak | 10.47 _57.2_| 9.56 _55.7_ | (3) | (2) Southwestern Alaska | 10.47 _57.6_| 9.80 _54.8_ | (15) | (16) Indian Point and Puotin | 10.54 _56.5_| 9.97 _56.5_ | (46) | (69) Nunivak Island | 10.55 _56.1_| 10.02 _56_ | | _Northwestern_ | | | (2) | Kotzebue | 10.45 _57.3_| | (133) | (82) Point Hope | 10.48 _57_ | 10.00 _56.9_ | (12) | (8) Shishmaref | 10.50 _56.8_| 10.20 _57.5_ | (47) | (52) Point Barrow | 10.54 _56.2_| 9.94 _55.5_ | (35) | (34) Barrow | 10.61 _55.9_| 10.01 _56.3_ | (19) | (15) Wales | 10.64 _56.7_| 10.01 _55.5_ | (27) | (24) Igloos north of Barrow | 10.70 _55.6_| 10.18 _56.2_ | | _Northern and northeastern_| | | (16) | (17) Baffin Land and vicinity | 10.51 _55.6_| 10.11 _55.2_ | (5) | (2) Hudson Bay and vicinity | 10.60 _56.4_| 9.75 _55.6_ | (48) | (52) Greenland | 10.60 _55.9_| 10.13 _56.2_ | (5) | (10) Northern Arctic | 10.68 _56.1_| 10.07 _55.3_ | (7) | Smith Sound | 10.70 _56.4_| | (9) | (5) Southampton Island | 10.83 _57.3_| 10.34 _56.9_ -----------------------------------------------------------

An interesting point is that in the north and northeast, where the skulls are longest, there is evidently a slightly greater relative development of the occipital portion of the vault, or slightly lesser development of the frontal portion.

Some additional points of interest appear when the basion-nasion: skull-length index, taken collectively for the two sexes, is compared in the different groups. All these comparisons suffer, naturally, from unevenness and often insufficiency of the numbers of specimens, yet some of the results are very harmonious with those brought out repeatedly by other data. Thus the St. Lawrence material stands once more close to the medium of the southwestern and midwestern groups; Barrow and Point Barrow are almost identical; and so are the Old Igloos from near Barrow and Greenland. The St. Michael islanders show very favorably in the midwest, the Shishmarefs in the northwest and the Southampton islanders in the northeast.

ESKIMO SKULLS: BASION-NASION LINE IN RELATION TO SKULL LENGTH

(BN×100/SL)

BOTH SEXES TOGETHER IN ASCENDING ORDER

_Southwestern and midwestern_

(5) Chukchee 54.8 (6) Pilot Station, Lower Yukon 55.2 (11) Little Diomede Island 55.6 (24) Nelson Island 55.9 (115) Nunivak Island 56.0 (10) Mumtrak 56.1 (279) St. Lawrence Island 56.2 (5) Southwestern Alaska 56.2 (29) Pastolik 56.4 (10) Togiak 56.5 (31) Indian Point and vicinity (Siberia) 56.5 (13) Hooper Bay 56.6 (14) St. Michael Island 56.8

_Northwestern_

(51) Igloos southwest of Barrow 55.9 (99) Point Barrow 55.9 (69) Barrow 56.1 (34) Wales 56.1 (215) Point Hope 57.0 (20) Shishmaref 57.1

_Northern and northeastern_

(33) Baffin Land and vicinity 55.4 (10) Northern Arctic 55.7 (7) Hudson Bay and vicinity 56.0 (100) Greenland 56.1 (7) Smith Sound (male) 56.4 (14) Southampton Island 57.1

The next table gives the percentage relations of the basion-nasion diameter to the mean diameter of the skull. The correlation of the two is even closer than in the case of the skull length, and the grouping, while in the main alike, seems in general even more in harmony with that in previous comparisons. The St. Lawrence Island females are very exceptional, as was also apparent in other connections. The unusual smallness of their skull (compare section on Cranial module) is evidently due to a poor development of its posterior half.

ESKIMO CRANIA: PERCENTAGE RELATION OF THE BASION-NASION DIAMETER TO MEAN CRANIAL DIAMETER (CRANIAL MODULE)

(BN×100/CM)

BOTH SEXES TOGETHER IN ASCENDING ORDER

_Southwestern and Midwestern_

Pilot Station, Yukon 65.6 Chukchee 66.0 Little Diomede Island 66.1 Hooper Bay 66.4 Nelson Island 66.7 Togiak 66.9 Southwest Alaska 67.3 Indian Point, Siberia 67.4 Mumtrak 67.4 Nunivak Island 67.6 Pastolik 67.6 St. Michael Island 68.0 St. Lawrence Island: Male 67.2 Female (69.6)

_Northwestern_

Wales 67.7 Point Barrow 67.8 Point Hope 68.1 Barrow 68.4 Old Igloos 69.0 Shishmaref 69.2

_Northern Arctic and northeastern_

Baffin Land 67.4 Hudson Bay 67.6 Smith Sound (male) 67.6 North Arctic 68.1 Greenland 68.5 Southampton Island 68.7

PROGNATHISM

Since better understood, the subject of facial prognathism has lost much of its allure in anthropology; yet the matter is not wholly without interest.

Facial protrusion is as a rule secondary to and largely caused by alveolar protrusion, which in turn is caused by the size and shape of the dental arch; and the dental arch is generally proportional to the size of the teeth. The form of the arch is, however, quite influential. With the teeth identical in size a narrow arch will be more, a broad arch less protruding, and a narrow arch with small teeth may protrude more than a broad one with larger teeth. Another influence is that of the height of the upper face, the same arch protruding more in a low face than in a high one. And still another factor is the incline of the front teeth, though this affects merely the appearance of prognathism and not its measurements.

There are different ways of measuring facial prognathism, and with sufficient care all may be effective; I prefer, for practical reasons, linear measurements from the basion, which, together with the facial and subnasal heights, give triangles that can readily be reconstructed on paper and allow a direct measurement of both the facial and the alveolar angle. The three needed diameters from basion are taken, the first to the "prealveolar point," or the _most anterior_ point on the upper dental arch above the incisors; the second to the "subnasal point," or the point on the left (for convenience) of the nasal aperture, where the outer part of its border passes into that which belongs to the subnasal portion of the maxilla (the point where the subnasal slant begins); and the third to nasion. The facial height is that from the alveolar point (_lowest_ point of the upper alveolar border in the median line) to nasion; while for the subnasal height, which can not be measured directly, I utilize the difference between the facial and nasal heights, which is very close to the needed dimension.

The important basion-nasion diameter has already been considered. That to the subnasal point needs no comment. That to the prealveolar point shows in the western and other Eskimo as follows:

ESKIMO CRANIA: BASION-PREALVEOLAR POINT DIAMETER

ALL ESKIMO

Males: Mean diameter centimeters 10.54 Mean relation to length of skull per cent _56.3_ Females: Diameter centimeters 9.99 Relation per cent _55.8_

MALES

A = Basion prealveolar point diameter B = Its relation to length of skull

+------------------+------------------+------------------+ | Southwestern and | Northwestern | Northern Arctics | | midwestern | | and northeastern | +------------------+------------------+------------------+ | _A_ _B_ | _A_ _B_ | _A_ _B_ | | 10.38 _56.4_ | 10.58 _56.4_ | 10.65 _56.2_ | | Mean skull lengths | | 18.41 | 18.75 | 18.96 | +------------------+------------------+------------------+ | FEMALES | +------------------+------------------+------------------+ | 9.85 _55.7_ | 10.06 _56.3_ | 10.06 _55.4_ | | Mean skull lengths | | 17.69 | 17.86 | 18.15 | +------------------+------------------+------------------+

As in other details, so here there is a remarkable similarity between the skulls from the three large areas, pointing both to the unity of the people and to absence of heterogeneous admixtures. As the skull length increases so does the basi-alveolar line, but the relative proportions of the two remain very nearly the same.

The relative value of the basi-alveolar length in the males, compared to the length of the skull, is in general about 0.5 per cent higher than it is in the females. This is just about the excess of the relative proportion of the length of the male dental arch when compared to the same skull dimension. The general mean skull length in the Eskimo male approximates 18.705, in female 17.899 centimeters; the mean length of the arch is, in the male, close to 5.625, in the female 5.365 centimeters; and the percentage relation of the latter to the former is _30.6_ in the males, _30_ in the females. The relatively slightly greater basi-alveolar length in the males is evidently, therefore, at least partly due to the relatively longer male dental arch, which in turn is doubtless due to the somewhat larger teeth in the males.[156]

Notwithstanding the just discussed slight sex difference in the Eskimo, the facial angle, i. e., the angle between the basi-alveolar line and the line nasion-alveolar point, is equal in the two sexes. This equalization is due largely, if not wholly, to the effect in the males of the relatively longer basio-nasion diameter (v. a.), while the alveolar angle, or that between the basi-alveolar and the subnasal lines, is in general by about 1 per cent lower in the females (males, 56°; females, 55°), indicating a slightly greater slant of the subnasal region in the female, which can only be due to a relatively slightly shorter in this sex of the basion-subnasal point diameter. As a matter of fact, the percentage relation of this diameter to the length of the skull amounts in the males to _56.3_, in the females to but _55.6_.

Compared to that in the Indians, the facial angle in the Eskimo skulls shows close affinities. Its value (69°) is very nearly the same as in the mound skulls from Arkansas and Louisiana (males 70.7°, females 69°). In other Indians it ranges from close to 68° to 71.5°. In the Munsee it reached 73.5°. In whites, according to Rivet's data,[157] it ranges from about 72° to 75°; in a group of negroes it was 68.5°. In American and other negro crania measured by me[158] it ranged from 67° to 70.5°, in Melanesians from 66° to 68°, in Australians from 67° to 69°.

The _alveolar angle_ is more variable. It shows considerable individual, sex, and group differences. It averages slightly to moderately higher, which means a more open angle or less slant in the males than in the females. In the Eskimo as a whole it was seen to be approximately 56° in the males, 55° in the females; in the Munsee Indians (Bull. 62, Bur. Amer. Ethn.) it was males 59°, females 57°; in the Arkansas and Louisiana skulls (J. Ac. Sci., Phila., 1909, XIV) it averaged males 55°, females 52°. In my catalogue material it shows a group variation of 46.5° to 55.5° in the negro, 47.5° to 52.5° in the Australians, 46.5° to 50.5° in the Melanesians. In the whites it generally exceeds 60°.

Differences in facial and alveolar protrusion among the Eskimo according to area are small, yet they are not wholly absent. The figures below show that in the southwesterners and midwesterners, where the skull is more rounded, the prognathism is smallest; and that toward the north and northeast, where the skull is narrower and the palate (dental arch) tends to become longer, prognathism increases. The "Old Igloo" group shows once more such affinity with the Greenlanders that it is placed with the third subdivision.

ESKIMO SKULLS: FACIAL AND ALVEOLAR ANGLE WITH PRINCIPAL AREAS

+---------------------------+--------------------------- | Males | Females +-------+---------+---------+-------+---------+--------- | South-| | North | South-| | North | and |Northwest| and | and |Northwest| and |midwest| |northeast|midwest| |northeast ----------------+-------+---------+---------+-------+---------+--------- Groups | (13) | (5) | (6) | (13) | (5) | (6) Facial angle | 68 | 69 | 70 | 67.5 | 69 | 70 Alveolar angle | 55 | 56 | 55 | 54 | 55 | 54.5 ----------------+-------+---------+---------+-------+---------+---------

Individual group differences in the facial and alveolar angle are moderate, yet evidently not negligible. (See next table.) The most prognathic, especially in the subnasal region, are the skulls from Nelson Island. A marked alveolar slant is also present in the Pilot Station Yukon group, and in Greenland. The least prognathic are the St. Michael Islanders, the Point Hope people, and those from Southampton Island. St. Lawrence stands once more near the middle of the southwesterners and midwesterners, and there are to be seen the principal old relations.

The main points shown by the above conditions are the group variability, particularly in the southwest and midwest; the tendency, on the whole, toward a slightly greater prognathy, both facial and alveolar, in this same area; and the evidence that the alveolar slant has some individuality.

ESKIMO SKULLS: GROUP CONDITIONS IN FACIAL AND ALVEOLAR ANGLE[159]

_South and Midwest_

Facial Alveolar angle angle (20) Nelson Island 66.3 51.5 (4) Southwest Alaska 66.8 54.5 (4) Chukchee 66.8 57.0 (21) Indian Point 67.0 56.5 (8) Togiak 67.0 54.0 (242) St. Lawrence Island 67.8 55.3 (86) Nunivak Island 67.8 56.5 (23) Pastolik 68.3 54.8 (10) Hooper Bay 68.3 55.3 (10) Little Diomede Island 68.5 57.5 (9) Mumtrak 68.8 55.3 (5) Pilot Station, Yukon 68.8 52.0 (10) St. Michael Island 70.0 56.8

_Northwest_

(11) Sledge Island 69.5 54.9 (31) Wales 67.8 56.0 (17) Shishmaref 68.3 55.8 (73) Point Barrow 69.5 56.0 (43) Barrow 69.8 56.8 (181) Point Hope 70.5 56.5

_North and northeast_